support design temperature

[nilaypathak]

Hello,

http://www.eng-tips.com/threadminder.cfm?pid=391

Thank you in advance for your time.

I am middle of finalize the stanchion design temperature, would like how to come up with correct design temperature. Stanchion are position vertical, open to both end in atmosphere, thus inside of the tube is atmosphere air. Stanchion outside skin expose to flue gas temperature, flue gas temperature 800C. Flue gas velocity could be assume 2m/s.

There will be heat sink as stanchion open to atmosphere. and I am bit struggling to find out tube metal temperature. Open for your thought.

Thanks,

 

[racookpe1978]

You have 30 feet of very small bore (2.875 inch OD) pipe exposed to 800 degree flue gas on the outside, and only natural convection (outside air rising from bottom to top of the open-ended vertical pipe) cooling inside.

Why do they think there will be any cooling of the pipe at all?

 

[nilaypathak]

thank you for your note.

There should be significant drop of temp inside the tube because of natural convection, but i am having difficulty to find outside tube temperature, flue gas side.

your point is valid, that's what i would like to find out too. Practically what should work.

Thanks again